Buggy code:
@ SuppressWarnings ( "unchecked" ) public < T > TypedQuery < T > createQuery ( String query , Class < T > resultClass ) { } public OpenJPAQuery createQuery ( String query ) { } public OpenJPAQuery createQuery ( String language , String query ) { } public OpenJPAQuery createQuery ( Query query ) { } @ SuppressWarnings ( "unchecked" ) public < T > TypedQuery < T > createNamedQuery ( String name , Class < T > resultClass ) { } public OpenJPAQuery createNamedQuery ( String name ) { } public OpenJPAQuery createNativeQuery ( String query ) { } public OpenJPAQuery createNativeQuery ( String query , Class cls ) { } public OpenJPAQuery createNativeQuery ( String query , String mappingName ) { } private static void validateSQL ( String query ) { } PreparedQueryCache getPreparedQueryCache ( ) { } PreparedQuery getPreparedQuery ( String id ) { } public void setFlushMode ( FlushModeType flushMode ) { } public FlushModeType getFlushMode ( ) { } static FlushModeType fromFlushBeforeQueries ( int flush ) { } static int toFlushBeforeQueries ( FlushModeType flushMode ) { } public void clear ( ) { } public Object getDelegate ( ) { } public LockModeType getLockMode ( Object entity ) { } public void lock ( Object entity , LockModeType mode ) { } public void lock ( Object entity ) { } public void lock ( Object entity , LockModeType mode , int timeout ) { } public void lock ( Object entity , LockModeType mode , Map < String , Object > properties ) { } public void lockAll ( Collection entities ) { } public void lockAll ( Collection entities , LockModeType mode , int timeout ) { } public void lockAll ( Object ... entities ) { } public void lockAll ( Object [ ] entities , LockModeType mode , int timeout ) { } public boolean cancelAll ( ) { } public Object getConnection ( ) { } public Collection getManagedObjects ( ) { } public Collection getTransactionalObjects ( ) { } public Collection getPendingTransactionalObjects ( ) { } public Collection getDirtyObjects ( ) { } public boolean getOrderDirtyObjects ( ) { } public void setOrderDirtyObjects ( boolean order ) { } public void dirtyClass ( Class cls ) { } @ SuppressWarnings ( "unchecked" ) public Collection < Class > getPersistedClasses ( ) { } @ SuppressWarnings ( "unchecked" ) public Collection < Class > getUpdatedClasses ( ) { } @ SuppressWarnings ( "unchecked" ) public Collection < Class > getRemovedClasses ( ) { } public < T > T createInstance ( Class < T > cls ) { } public void close ( ) { } public boolean isOpen ( ) { } public void dirty ( Object o , String field ) { } public Object getObjectId ( Object o ) { } public boolean isDirty ( Object o ) { } public boolean isTransactional ( Object o ) { } public boolean isPersistent ( Object o ) { } public boolean isNewlyPersistent ( Object o ) { } public boolean isRemoved ( Object o ) { } public boolean isDetached ( Object entity ) { } public Object getVersion ( Object o ) { } void assertNotCloseInvoked ( ) { } void assertValidAttchedEntity ( String call , Object entity ) { } public Object processArgument ( Object arg ) { } public Object processReturn ( Object oid , OpenJPAStateManager sm ) { } public int processArgument ( int op , Object obj , OpenJPAStateManager sm ) { } public int hashCode ( ) { } public boolean equals ( Object other ) { } public void readExternal ( ObjectInput in ) throws IOException , ClassNotFoundException { } public void writeExternal ( ObjectOutput out ) throws IOException { } private static class BrokerBytesInputStream extends ObjectInputStream { private OpenJPAConfiguration conf ; BrokerBytesInputStream ( byte [ ] bytes , OpenJPAConfiguration conf ) throws IOException { } private Class primitiveType ( char type ) { } protected Class < ? > resolveClass ( ObjectStreamClass classDesc ) throws IOException , ClassNotFoundException { } private Class < ? > lookupClass ( String className ) throws ClassNotFoundException { } } public void detach ( Object entity ) { } public < T > TypedQuery < T > createQuery ( CriteriaQuery < T > criteriaQuery ) { } public OpenJPAQuery createDynamicQuery ( QueryDefinition qdef ) { } public Map < String , Object > getProperties ( ) { } public OpenJPACriteriaBuilder getCriteriaBuilder ( ) { } public Set < String > getSupportedProperties ( ) { } public < T > T unwrap ( Class < T > cls ) { } public void setQuerySQLCache ( boolean flag ) { } public boolean getQuerySQLCache ( ) { } RuntimeExceptionTranslator getExceptionTranslator ( ) { } private void configureCurrentFetchPlan ( FetchPlan fetch , Map < String , Object > properties , LockModeType lock , boolean requiresTxn ) { } private void configureCurrentCacheModes ( FetchPlan fetch , Map < String , Object > properties ) { } public Metamodel getMetamodel ( ) { } public void setProperty ( String prop , Object value ) { if ( ! ( setKernelProperty ( this , prop , value ) ) ) { if ( ! ( setKernelProperty ( this . getFetchPlan ( ) , prop , value ) ) ) { Log log = getConfiguration ( ) . getLog ( LOG_RUNTIME ) ; if ( log . isWarnEnabled ( ) ) { <START_BUG> log . warn ( EntityManagerImpl . _loc . get ( "bad-em-prop" , prop , ( value == null ? "" : ( ( value . getClass ( ) ) + ":" ) + value ) ) ) ; <END_BUG> } } } } private boolean setKernelProperty ( Object target , String original , Object value ) { } String getBeanPropertyName ( String user ) { } Object convertUserValue ( String key , Object value , Class < ? > targetType ) { } }

Fix:
log . warn ( EntityManagerImpl . _loc . get ( "ignored-em-prop" , prop , ( value == null ? "" : ( ( value . getClass ( ) ) + ":" ) + value ) ) ) ;